The present invention relates to a wet-operated armature for an electric machine, in particular of an electric fuel pump, and to a method for producing the armature.
Wet-operated armatures are frequently sheathed by means of a spray-coating or painting process, in order to seal them against surrounding liquid. Mostly, however, such a sealing is not completely tight. Moreover, it is often the case that the liquids that surround wet-operated armatures are electrically conductive and/or aggressive. This is the case, for example, with fuel pumps, in which the liquid is a fuel, for example (bio-)diesel or petrol.
Such liquids penetrate the hitherto known sheathings, or attack and damage the hitherto known sheathings, until the sealing is no longer assured and the windings of the armature are exposed. The latter are then attacked and damaged by the liquid, this ultimately resulting in a winding short-circuit and consequently in the failure of the motor.